[clang] 0dac639 - [Clang][Sema] Capturing section type conflicts on #pragma clang section

[Lucas Prates via cfe-commits]

Author: Lucas Prates
Date: 2020-05-07T11:53:30+01:00
New Revision: 0dac639f285a53dffe3239ec5561fa0fc2da0daf

URL: https://github.com/llvm/llvm-project/commit/0dac639f285a53dffe3239ec5561fa0fc2da0daf
DIFF: https://github.com/llvm/llvm-project/commit/0dac639f285a53dffe3239ec5561fa0fc2da0daf.diff

LOG: [Clang][Sema] Capturing section type conflicts on #pragma clang section

Summary:
Section names used in clang section pragmas were not validated against
previously defined sections, causing section type conflicts to be
ignored by Sema.

This patch enables Clang to capture these section type conflicts by
using the existing Sema's UnifySection method to validate section names
from clang section pragmas.

Reviewers: hans, rnk, javed.absar

Reviewed By: rnk

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78572

Added: 
    

Modified: 
    clang/include/clang/AST/ASTContext.h
    clang/lib/Parse/ParsePragma.cpp
    clang/lib/Sema/SemaAttr.cpp
    clang/test/Sema/pragma-clang-section.c

Removed: 
    


################################################################################
diff  --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index cd7021a5884b..5f8e7fceabc0 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -2978,6 +2978,7 @@ OPT_LIST(V)
     PSF_Write = 0x2,
     PSF_Execute = 0x4,
     PSF_Implicit = 0x8,
+    PSF_ZeroInit = 0x10,
     PSF_Invalid = 0x80000000U,
   };
 

diff  --git a/clang/lib/Parse/ParsePragma.cpp b/clang/lib/Parse/ParsePragma.cpp
index 828d429e6969..816aaf9f0956 100644
--- a/clang/lib/Parse/ParsePragma.cpp
+++ b/clang/lib/Parse/ParsePragma.cpp
@@ -1873,6 +1873,7 @@ void PragmaClangSectionHandler::HandlePragma(Preprocessor &PP,
       return;
     }
 
+    SourceLocation PragmaLocation = Tok.getLocation();
     PP.Lex(Tok); // eat ['bss'|'data'|'rodata'|'text']
     if (Tok.isNot(tok::equal)) {
       PP.Diag(Tok.getLocation(), diag::err_pragma_clang_section_expected_equal) << SecKind;
@@ -1883,10 +1884,11 @@ void PragmaClangSectionHandler::HandlePragma(Preprocessor &PP,
     if (!PP.LexStringLiteral(Tok, SecName, "pragma clang section", false))
       return;
 
-    Actions.ActOnPragmaClangSection(Tok.getLocation(),
-      (SecName.size()? Sema::PragmaClangSectionAction::PCSA_Set :
-                       Sema::PragmaClangSectionAction::PCSA_Clear),
-       SecKind, SecName);
+    Actions.ActOnPragmaClangSection(
+        PragmaLocation,
+        (SecName.size() ? Sema::PragmaClangSectionAction::PCSA_Set
+                        : Sema::PragmaClangSectionAction::PCSA_Clear),
+        SecKind, SecName);
   }
 }
 

diff  --git a/clang/lib/Sema/SemaAttr.cpp b/clang/lib/Sema/SemaAttr.cpp
index 50089dea7759..b5cb96dff44b 100644
--- a/clang/lib/Sema/SemaAttr.cpp
+++ b/clang/lib/Sema/SemaAttr.cpp
@@ -256,12 +256,15 @@ void Sema::ActOnPragmaOptionsAlign(PragmaOptionsAlignKind Kind,
 void Sema::ActOnPragmaClangSection(SourceLocation PragmaLoc, PragmaClangSectionAction Action,
                                    PragmaClangSectionKind SecKind, StringRef SecName) {
   PragmaClangSection *CSec;
+  int SectionFlags = ASTContext::PSF_Read;
   switch (SecKind) {
     case PragmaClangSectionKind::PCSK_BSS:
       CSec = &PragmaClangBSSSection;
+      SectionFlags |= ASTContext::PSF_Write | ASTContext::PSF_ZeroInit;
       break;
     case PragmaClangSectionKind::PCSK_Data:
       CSec = &PragmaClangDataSection;
+      SectionFlags |= ASTContext::PSF_Write;
       break;
     case PragmaClangSectionKind::PCSK_Rodata:
       CSec = &PragmaClangRodataSection;
@@ -271,6 +274,7 @@ void Sema::ActOnPragmaClangSection(SourceLocation PragmaLoc, PragmaClangSectionA
       break;
     case PragmaClangSectionKind::PCSK_Text:
       CSec = &PragmaClangTextSection;
+      SectionFlags |= ASTContext::PSF_Execute;
       break;
     default:
       llvm_unreachable("invalid clang section kind");
@@ -281,6 +285,9 @@ void Sema::ActOnPragmaClangSection(SourceLocation PragmaLoc, PragmaClangSectionA
     return;
   }
 
+  if (UnifySection(SecName, SectionFlags, PragmaLoc))
+    return;
+
   CSec->Valid = true;
   CSec->SectionName = std::string(SecName);
   CSec->PragmaLocation = PragmaLoc;

diff  --git a/clang/test/Sema/pragma-clang-section.c b/clang/test/Sema/pragma-clang-section.c
index 38a3bc92744f..97d10f5f11c3 100644
--- a/clang/test/Sema/pragma-clang-section.c
+++ b/clang/test/Sema/pragma-clang-section.c
@@ -1,5 +1,5 @@
 // RUN: %clang_cc1 -fsyntax-only -verify %s -triple arm-none-eabi
-#pragma clang section bss="mybss.1" data="mydata.1" rodata="myrodata.1" text="mytext.1"
+#pragma clang section bss = "mybss.1" data = "mydata.1" rodata = "myrodata.1" text = "mytext.1" // expected-note 2 {{#pragma entered here}}
 #pragma clang section bss="" data="" rodata="" text=""
 #pragma clang section
 
@@ -16,4 +16,10 @@
 #pragma clang section text "text.2"   // expected-error {{expected '=' following '#pragma clang section text'}}
 #pragma clang section relro "relro.2"   // expected-error {{expected '=' following '#pragma clang section relro'}}
 #pragma clang section bss="" data="" rodata="" text="" more //expected-error {{expected one of [bss|data|rodata|text|relro] section kind in '#pragma clang section'}}
+
+#pragma clang section bss = "mybss.3" data = "mybss.3" // expected-error {{this causes a section type conflict with a prior #pragma section}} expected-note {{#pragma entered here}} expected-note {{#pragma entered here}}
+#pragma clang section rodata = "mydata.1"              // expected-error {{this causes a section type conflict with a prior #pragma section}}
+#pragma clang section bss = "myrodata.1"               // expected-error {{this causes a section type conflict with a prior #pragma section}}
+#pragma clang section text = "mybss.3"                 // expected-error {{this causes a section type conflict with a prior #pragma section}}
+
 int a;