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, 51 insertions, 47 deletions

diff --git a/fpdfsdk/fpdfeditpath.cpp b/fpdfsdk/fpdfeditpath.cpp
index 2181df8406..19d47e6a44 100644
--- a/fpdfsdk/fpdfeditpath.cpp
+++ b/fpdfsdk/fpdfeditpath.cpp
@@ -26,28 +26,30 @@ static_assert(CFX_GraphStateData::LineJoinRound == FPDF_LINEJOIN_ROUND,
 static_assert(CFX_GraphStateData::LineJoinBevel == FPDF_LINEJOIN_BEVEL,
               "CFX_GraphStateData::LineJoinBevel value mismatch");
 
-DLLEXPORT FPDF_PAGEOBJECT STDCALL FPDFPageObj_CreateNewPath(float x, float y) {
+FPDF_EXPORT FPDF_PAGEOBJECT FPDF_CALLCONV FPDFPageObj_CreateNewPath(float x,
+                                                                    float y) {
   auto pPathObj = pdfium::MakeUnique<CPDF_PathObject>();
   pPathObj->m_Path.AppendPoint(CFX_PointF(x, y), FXPT_TYPE::MoveTo, false);
   pPathObj->DefaultStates();
   return pPathObj.release();  // Caller takes ownership.
 }
 
-DLLEXPORT FPDF_PAGEOBJECT STDCALL FPDFPageObj_CreateNewRect(float x,
-                                                            float y,
-                                                            float w,
-                                                            float h) {
+FPDF_EXPORT FPDF_PAGEOBJECT FPDF_CALLCONV FPDFPageObj_CreateNewRect(float x,
+                                                                    float y,
+                                                                    float w,
+                                                                    float h) {
   auto pPathObj = pdfium::MakeUnique<CPDF_PathObject>();
   pPathObj->m_Path.AppendRect(x, y, x + w, y + h);
   pPathObj->DefaultStates();
   return pPathObj.release();  // Caller takes ownership.
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_SetStrokeColor(FPDF_PAGEOBJECT path,
-                                                    unsigned int R,
-                                                    unsigned int G,
-                                                    unsigned int B,
-                                                    unsigned int A) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV
+FPDFPath_SetStrokeColor(FPDF_PAGEOBJECT path,
+                        unsigned int R,
+                        unsigned int G,
+                        unsigned int B,
+                        unsigned int A) {
   if (!path || R > 255 || G > 255 || B > 255 || A > 255)
     return false;
 
@@ -60,11 +62,12 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFPath_SetStrokeColor(FPDF_PAGEOBJECT path,
   return true;
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_GetStrokeColor(FPDF_PAGEOBJECT path,
-                                                    unsigned int* R,
-                                                    unsigned int* G,
-                                                    unsigned int* B,
-                                                    unsigned int* A) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV
+FPDFPath_GetStrokeColor(FPDF_PAGEOBJECT path,
+                        unsigned int* R,
+                        unsigned int* G,
+                        unsigned int* B,
+                        unsigned int* A) {
   if (!path || !R || !G || !B || !A)
     return false;
 
@@ -78,8 +81,8 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFPath_GetStrokeColor(FPDF_PAGEOBJECT path,
   return true;
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_SetStrokeWidth(FPDF_PAGEOBJECT path,
-                                                    float width) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV
+FPDFPath_SetStrokeWidth(FPDF_PAGEOBJECT path, float width) {
   if (!path || width < 0.0f)
     return false;
 
@@ -89,19 +92,19 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFPath_SetStrokeWidth(FPDF_PAGEOBJECT path,
   return true;
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_SetFillColor(FPDF_PAGEOBJECT path,
-                                                  unsigned int R,
-                                                  unsigned int G,
-                                                  unsigned int B,
-                                                  unsigned int A) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_SetFillColor(FPDF_PAGEOBJECT path,
+                                                          unsigned int R,
+                                                          unsigned int G,
+                                                          unsigned int B,
+                                                          unsigned int A) {
   return FPDFPageObj_SetFillColor(path, R, G, B, A);
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_GetFillColor(FPDF_PAGEOBJECT path,
-                                                  unsigned int* R,
-                                                  unsigned int* G,
-                                                  unsigned int* B,
-                                                  unsigned int* A) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_GetFillColor(FPDF_PAGEOBJECT path,
+                                                          unsigned int* R,
+                                                          unsigned int* G,
+                                                          unsigned int* B,
+                                                          unsigned int* A) {
   if (!path || !R || !G || !B || !A)
     return false;
 
@@ -115,9 +118,9 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFPath_GetFillColor(FPDF_PAGEOBJECT path,
   return true;
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_MoveTo(FPDF_PAGEOBJECT path,
-                                            float x,
-                                            float y) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_MoveTo(FPDF_PAGEOBJECT path,
+                                                    float x,
+                                                    float y) {
   if (!path)
     return false;
 
@@ -127,9 +130,9 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFPath_MoveTo(FPDF_PAGEOBJECT path,
   return true;
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_LineTo(FPDF_PAGEOBJECT path,
-                                            float x,
-                                            float y) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_LineTo(FPDF_PAGEOBJECT path,
+                                                    float x,
+                                                    float y) {
   if (!path)
     return false;
 
@@ -139,13 +142,13 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFPath_LineTo(FPDF_PAGEOBJECT path,
   return true;
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_BezierTo(FPDF_PAGEOBJECT path,
-                                              float x1,
-                                              float y1,
-                                              float x2,
-                                              float y2,
-                                              float x3,
-                                              float y3) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_BezierTo(FPDF_PAGEOBJECT path,
+                                                      float x1,
+                                                      float y1,
+                                                      float x2,
+                                                      float y2,
+                                                      float x3,
+                                                      float y3) {
   if (!path)
     return false;
 
@@ -157,7 +160,7 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFPath_BezierTo(FPDF_PAGEOBJECT path,
   return true;
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_Close(FPDF_PAGEOBJECT path) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_Close(FPDF_PAGEOBJECT path) {
   if (!path)
     return false;
 
@@ -170,9 +173,9 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFPath_Close(FPDF_PAGEOBJECT path) {
   return true;
 }
 
-DLLEXPORT FPDF_BOOL STDCALL FPDFPath_SetDrawMode(FPDF_PAGEOBJECT path,
-                                                 int fillmode,
-                                                 FPDF_BOOL stroke) {
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_SetDrawMode(FPDF_PAGEOBJECT path,
+                                                         int fillmode,
+                                                         FPDF_BOOL stroke) {
   if (!path)
     return false;
 
@@ -189,8 +192,8 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFPath_SetDrawMode(FPDF_PAGEOBJECT path,
   return true;
 }
 
-DLLEXPORT void STDCALL FPDFPath_SetLineJoin(FPDF_PAGEOBJECT path,
-                                            int line_join) {
+FPDF_EXPORT void FPDF_CALLCONV FPDFPath_SetLineJoin(FPDF_PAGEOBJECT path,
+                                                    int line_join) {
   if (!path)
     return;
   if (line_join <
@@ -206,7 +209,8 @@ DLLEXPORT void STDCALL FPDFPath_SetLineJoin(FPDF_PAGEOBJECT path,
   pPathObj->SetDirty(true);
 }
 
-DLLEXPORT void STDCALL FPDFPath_SetLineCap(FPDF_PAGEOBJECT path, int line_cap) {
+FPDF_EXPORT void FPDF_CALLCONV FPDFPath_SetLineCap(FPDF_PAGEOBJECT path,
+                                                   int line_cap) {
   if (!path)
     return;
   if (line_cap < static_cast<int>(CFX_GraphStateData::LineCap::LineCapButt) ||