Add a build target and a proper export header for shared library builds.

This CL adds support for Chromium's component build feature to pdfium.

The export header stub in fpdfview.h is expanded to match Chromium's
export mechanisms and patterns (fixes pdfium:825).

A component/shared library build can be triggered by adding

is_component_build = true

as a gn argument. Please note that setting this will also affect some
of pdfiums dependencies like v8, which will be build as components
too.

Additionally, this CL provides a "pdf_source_set" template which
dynamically enables the use of "source_set" when building a complete
static library or a shared library to reduce build time.

When testing this it is recommended to only build the pdfium target as
most of pdfiums test rely on non-public functions which aren't exported
by the shared library.

Bug: pdfium:825,pdfium:826
Change-Id: Icedc538ec535e11d1e53c4d5fabc8c064b275752
Reviewed-on: https://pdfium-review.googlesource.com/8970
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

1 files changed, 66 insertions, 63 deletions

diff --git a/public/fpdf_text.h b/public/fpdf_text.h
index 5c241527eb..c069144026 100644
--- a/public/fpdf_text.h
+++ b/public/fpdf_text.h
@@ -27,7 +27,7 @@ extern "C" {
 //          Application must call FPDFText_ClosePage to release the text page
 //          information.
 //
-DLLEXPORT FPDF_TEXTPAGE STDCALL FPDFText_LoadPage(FPDF_PAGE page);
+FPDF_EXPORT FPDF_TEXTPAGE FPDF_CALLCONV FPDFText_LoadPage(FPDF_PAGE page);
 
 // Function: FPDFText_ClosePage
 //          Release all resources allocated for a text page information
@@ -38,7 +38,7 @@ DLLEXPORT FPDF_TEXTPAGE STDCALL FPDFText_LoadPage(FPDF_PAGE page);
 // Return Value:
 //          None.
 //
-DLLEXPORT void STDCALL FPDFText_ClosePage(FPDF_TEXTPAGE text_page);
+FPDF_EXPORT void FPDF_CALLCONV FPDFText_ClosePage(FPDF_TEXTPAGE text_page);
 
 // Function: FPDFText_CountChars
 //          Get number of characters in a page.
@@ -56,7 +56,7 @@ DLLEXPORT void STDCALL FPDFText_ClosePage(FPDF_TEXTPAGE text_page);
 //          first character in the page
 //          has an index value of zero.
 //
-DLLEXPORT int STDCALL FPDFText_CountChars(FPDF_TEXTPAGE text_page);
+FPDF_EXPORT int FPDF_CALLCONV FPDFText_CountChars(FPDF_TEXTPAGE text_page);
 
 // Function: FPDFText_GetUnicode
 //          Get Unicode of a character in a page.
@@ -70,8 +70,8 @@ DLLEXPORT int STDCALL FPDFText_CountChars(FPDF_TEXTPAGE text_page);
 //          convert to Unicode,
 //          the return value will be zero.
 //
-DLLEXPORT unsigned int STDCALL FPDFText_GetUnicode(FPDF_TEXTPAGE text_page,
-                                                   int index);
+FPDF_EXPORT unsigned int FPDF_CALLCONV
+FPDFText_GetUnicode(FPDF_TEXTPAGE text_page, int index);
 
 // Function: FPDFText_GetFontSize
 //          Get the font size of a particular character.
@@ -84,8 +84,8 @@ DLLEXPORT unsigned int STDCALL FPDFText_GetUnicode(FPDF_TEXTPAGE text_page,
 //          1/72 inch).
 //          This is the typographic size of the font (so called "em size").
 //
-DLLEXPORT double STDCALL FPDFText_GetFontSize(FPDF_TEXTPAGE text_page,
-                                              int index);
+FPDF_EXPORT double FPDF_CALLCONV FPDFText_GetFontSize(FPDF_TEXTPAGE text_page,
+                                                      int index);
 
 // Function: FPDFText_GetCharBox
 //          Get bounding box of a particular character.
@@ -106,12 +106,12 @@ DLLEXPORT double STDCALL FPDFText_GetFontSize(FPDF_TEXTPAGE text_page,
 // Comments:
 //          All positions are measured in PDF "user space".
 //
-DLLEXPORT void STDCALL FPDFText_GetCharBox(FPDF_TEXTPAGE text_page,
-                                           int index,
-                                           double* left,
-                                           double* right,
-                                           double* bottom,
-                                           double* top);
+FPDF_EXPORT void FPDF_CALLCONV FPDFText_GetCharBox(FPDF_TEXTPAGE text_page,
+                                                   int index,
+                                                   double* left,
+                                                   double* right,
+                                                   double* bottom,
+                                                   double* top);
 
 // Function: FPDFText_GetCharIndexAtPos
 //          Get the index of a character at or nearby a certain position on the
@@ -131,11 +131,12 @@ DLLEXPORT void STDCALL FPDFText_GetCharBox(FPDF_TEXTPAGE text_page,
 //          be -1.
 //          If an error occurs, -3 will be returned.
 //
-DLLEXPORT int STDCALL FPDFText_GetCharIndexAtPos(FPDF_TEXTPAGE text_page,
-                                                 double x,
-                                                 double y,
-                                                 double xTolerance,
-                                                 double yTolerance);
+FPDF_EXPORT int FPDF_CALLCONV
+FPDFText_GetCharIndexAtPos(FPDF_TEXTPAGE text_page,
+                           double x,
+                           double y,
+                           double xTolerance,
+                           double yTolerance);
 
 // Function: FPDFText_GetText
 //          Extract unicode text string from the page.
@@ -154,10 +155,10 @@ DLLEXPORT int STDCALL FPDFText_GetCharIndexAtPos(FPDF_TEXTPAGE text_page,
 // Comments:
 //          This function ignores characters without unicode information.
 //
-DLLEXPORT int STDCALL FPDFText_GetText(FPDF_TEXTPAGE text_page,
-                                       int start_index,
-                                       int count,
-                                       unsigned short* result);
+FPDF_EXPORT int FPDF_CALLCONV FPDFText_GetText(FPDF_TEXTPAGE text_page,
+                                               int start_index,
+                                               int count,
+                                               unsigned short* result);
 
 // Function: FPDFText_CountRects
 //          Count number of rectangular areas occupied by a segment of texts.
@@ -177,9 +178,9 @@ DLLEXPORT int STDCALL FPDFText_GetText(FPDF_TEXTPAGE text_page,
 //          one if those characters
 //          are on the same line and use same font settings.
 //
-DLLEXPORT int STDCALL FPDFText_CountRects(FPDF_TEXTPAGE text_page,
-                                          int start_index,
-                                          int count);
+FPDF_EXPORT int FPDF_CALLCONV FPDFText_CountRects(FPDF_TEXTPAGE text_page,
+                                                  int start_index,
+                                                  int count);
 
 // Function: FPDFText_GetRect
 //          Get a rectangular area from the result generated by
@@ -199,12 +200,12 @@ DLLEXPORT int STDCALL FPDFText_CountRects(FPDF_TEXTPAGE text_page,
 // Return Value:
 //          None.
 //
-DLLEXPORT void STDCALL FPDFText_GetRect(FPDF_TEXTPAGE text_page,
-                                        int rect_index,
-                                        double* left,
-                                        double* top,
-                                        double* right,
-                                        double* bottom);
+FPDF_EXPORT void FPDF_CALLCONV FPDFText_GetRect(FPDF_TEXTPAGE text_page,
+                                                int rect_index,
+                                                double* left,
+                                                double* top,
+                                                double* right,
+                                                double* bottom);
 
 // Function: FPDFText_GetBoundedText
 //          Extract unicode text within a rectangular boundary on the page.
@@ -232,13 +233,13 @@ DLLEXPORT void STDCALL FPDFText_GetRect(FPDF_TEXTPAGE text_page,
 //          If the buffer is too small, as much text as will fit is copied into
 //          it.
 //
-DLLEXPORT int STDCALL FPDFText_GetBoundedText(FPDF_TEXTPAGE text_page,
-                                              double left,
-                                              double top,
-                                              double right,
-                                              double bottom,
-                                              unsigned short* buffer,
-                                              int buflen);
+FPDF_EXPORT int FPDF_CALLCONV FPDFText_GetBoundedText(FPDF_TEXTPAGE text_page,
+                                                      double left,
+                                                      double top,
+                                                      double right,
+                                                      double bottom,
+                                                      unsigned short* buffer,
+                                                      int buflen);
 
 // Flags used by FPDFText_FindStart function.
 #define FPDF_MATCHCASE \
@@ -258,10 +259,11 @@ DLLEXPORT int STDCALL FPDFText_GetBoundedText(FPDF_TEXTPAGE text_page,
 //          A handle for the search context. FPDFText_FindClose must be called
 //          to release this handle.
 //
-DLLEXPORT FPDF_SCHHANDLE STDCALL FPDFText_FindStart(FPDF_TEXTPAGE text_page,
-                                                    FPDF_WIDESTRING findwhat,
-                                                    unsigned long flags,
-                                                    int start_index);
+FPDF_EXPORT FPDF_SCHHANDLE FPDF_CALLCONV
+FPDFText_FindStart(FPDF_TEXTPAGE text_page,
+                   FPDF_WIDESTRING findwhat,
+                   unsigned long flags,
+                   int start_index);
 
 // Function: FPDFText_FindNext
 //          Search in the direction from page start to end.
@@ -271,7 +273,7 @@ DLLEXPORT FPDF_SCHHANDLE STDCALL FPDFText_FindStart(FPDF_TEXTPAGE text_page,
 // Return Value:
 //          Whether a match is found.
 //
-DLLEXPORT FPDF_BOOL STDCALL FPDFText_FindNext(FPDF_SCHHANDLE handle);
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFText_FindNext(FPDF_SCHHANDLE handle);
 
 // Function: FPDFText_FindPrev
 //          Search in the direction from page end to start.
@@ -281,7 +283,7 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFText_FindNext(FPDF_SCHHANDLE handle);
 // Return Value:
 //          Whether a match is found.
 //
-DLLEXPORT FPDF_BOOL STDCALL FPDFText_FindPrev(FPDF_SCHHANDLE handle);
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFText_FindPrev(FPDF_SCHHANDLE handle);
 
 // Function: FPDFText_GetSchResultIndex
 //          Get the starting character index of the search result.
@@ -291,7 +293,7 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFText_FindPrev(FPDF_SCHHANDLE handle);
 // Return Value:
 //          Index for the starting character.
 //
-DLLEXPORT int STDCALL FPDFText_GetSchResultIndex(FPDF_SCHHANDLE handle);
+FPDF_EXPORT int FPDF_CALLCONV FPDFText_GetSchResultIndex(FPDF_SCHHANDLE handle);
 
 // Function: FPDFText_GetSchCount
 //          Get the number of matched characters in the search result.
@@ -301,7 +303,7 @@ DLLEXPORT int STDCALL FPDFText_GetSchResultIndex(FPDF_SCHHANDLE handle);
 // Return Value:
 //          Number of matched characters.
 //
-DLLEXPORT int STDCALL FPDFText_GetSchCount(FPDF_SCHHANDLE handle);
+FPDF_EXPORT int FPDF_CALLCONV FPDFText_GetSchCount(FPDF_SCHHANDLE handle);
 
 // Function: FPDFText_FindClose
 //          Release a search context.
@@ -311,7 +313,7 @@ DLLEXPORT int STDCALL FPDFText_GetSchCount(FPDF_SCHHANDLE handle);
 // Return Value:
 //          None.
 //
-DLLEXPORT void STDCALL FPDFText_FindClose(FPDF_SCHHANDLE handle);
+FPDF_EXPORT void FPDF_CALLCONV FPDFText_FindClose(FPDF_SCHHANDLE handle);
 
 // Function: FPDFLink_LoadWebLinks
 //          Prepare information about weblinks in a page.
@@ -336,7 +338,8 @@ DLLEXPORT void STDCALL FPDFText_FindClose(FPDF_SCHHANDLE handle);
 //
 //          FPDFLink_CloseWebLinks must be called to release resources.
 //
-DLLEXPORT FPDF_PAGELINK STDCALL FPDFLink_LoadWebLinks(FPDF_TEXTPAGE text_page);
+FPDF_EXPORT FPDF_PAGELINK FPDF_CALLCONV
+FPDFLink_LoadWebLinks(FPDF_TEXTPAGE text_page);
 
 // Function: FPDFLink_CountWebLinks
 //          Count number of detected web links.
@@ -345,7 +348,7 @@ DLLEXPORT FPDF_PAGELINK STDCALL FPDFLink_LoadWebLinks(FPDF_TEXTPAGE text_page);
 // Return Value:
 //          Number of detected web links.
 //
-DLLEXPORT int STDCALL FPDFLink_CountWebLinks(FPDF_PAGELINK link_page);
+FPDF_EXPORT int FPDF_CALLCONV FPDFLink_CountWebLinks(FPDF_PAGELINK link_page);
 
 // Function: FPDFLink_GetURL
 //          Fetch the URL information for a detected web link.
@@ -366,10 +369,10 @@ DLLEXPORT int STDCALL FPDFLink_CountWebLinks(FPDF_PAGELINK link_page);
 //          If |link_index| does not correspond to a valid link, then the result
 //          is an empty string.
 //
-DLLEXPORT int STDCALL FPDFLink_GetURL(FPDF_PAGELINK link_page,
-                                      int link_index,
-                                      unsigned short* buffer,
-                                      int buflen);
+FPDF_EXPORT int FPDF_CALLCONV FPDFLink_GetURL(FPDF_PAGELINK link_page,
+                                              int link_index,
+                                              unsigned short* buffer,
+                                              int buflen);
 
 // Function: FPDFLink_CountRects
 //          Count number of rectangular areas for the link.
@@ -380,8 +383,8 @@ DLLEXPORT int STDCALL FPDFLink_GetURL(FPDF_PAGELINK link_page,
 //          Number of rectangular areas for the link.  If |link_index| does
 //          not correspond to a valid link, then 0 is returned.
 //
-DLLEXPORT int STDCALL FPDFLink_CountRects(FPDF_PAGELINK link_page,
-                                          int link_index);
+FPDF_EXPORT int FPDF_CALLCONV FPDFLink_CountRects(FPDF_PAGELINK link_page,
+                                                  int link_index);
 
 // Function: FPDFLink_GetRect
 //          Fetch the boundaries of a rectangle for a link.
@@ -401,13 +404,13 @@ DLLEXPORT int STDCALL FPDFLink_CountRects(FPDF_PAGELINK link_page,
 //          None.  If |link_index| does not correspond to a valid link, then
 //          |left|, |top|, |right|, and |bottom| remain unmodified.
 //
-DLLEXPORT void STDCALL FPDFLink_GetRect(FPDF_PAGELINK link_page,
-                                        int link_index,
-                                        int rect_index,
-                                        double* left,
-                                        double* top,
-                                        double* right,
-                                        double* bottom);
+FPDF_EXPORT void FPDF_CALLCONV FPDFLink_GetRect(FPDF_PAGELINK link_page,
+                                                int link_index,
+                                                int rect_index,
+                                                double* left,
+                                                double* top,
+                                                double* right,
+                                                double* bottom);
 
 // Function: FPDFLink_CloseWebLinks
 //          Release resources used by weblink feature.
@@ -416,7 +419,7 @@ DLLEXPORT void STDCALL FPDFLink_GetRect(FPDF_PAGELINK link_page,
 // Return Value:
 //          None.
 //
-DLLEXPORT void STDCALL FPDFLink_CloseWebLinks(FPDF_PAGELINK link_page);
+FPDF_EXPORT void FPDF_CALLCONV FPDFLink_CloseWebLinks(FPDF_PAGELINK link_page);
 
 #ifdef __cplusplus
 }